Shouldn't that other chartag be kanaki_anzu? There are no kaneki_kyouko in Another.

http://ja.wikipedia.org/wiki/Another confirming that it is in fact kaneki_kyouko: 金木 杏子（かねき きょうこ）
I wonder where anidb/mal got their reading from?

I looked at Japanese Wikipedia too, and that's why I changed it, though to be honest, I'm unsure if the reading is official. If there is no official source listing the name readings of the class members, than pretty much any reading of her name (whether it be a Japanese wiki or anidb/mal) is just guesswork.